I've been running a DF adventure at conventions and other events since 2011. I have a collection of pregenerated characters and I've allowed many of the players to make their own characters as well.
Every session started and ended in the tavern so there was no concern about having different players at the table each session.
I've had a few other GMs offer to run it, often so I can be a player.
I'm switching to DFRPG(PBG) and with that switch, I'm ending the old campaign and starting a new one. 21 of the nearly 80 characters transferred to the new setting.
The new campaign will be centered in a huge city and I'm handling the other GMs by letting each of them create an organization that will be their default quest giver. There will be "public" organizations as well, but the owned ones will give their quests a commonality. Maybe each quest is a piece of a puzzle.

I'm sharing this for a few reasons. Primarily because I'm interested in your collective input and suggestions that might help this idea flourish the way I'm hoping it will.

If you haven't decided on a specific setting yet, Ptolus might be a good choice - it is a massive city with dungeons both below and above cities, and even has a guild for adventurer delving into them (the "Delver's Guild"). There is at least one person running a Dungeon Fantasy game in it, in fact.

We've nailed down only vague necessities. The existence of all of the things necessary such as sewers, ruins, a river, nearby mountains, nearby woodlands, etc. So switching what we're doing to an existing city like that wouldn't be painful really.

We've nailed down only vague necessities. The existence of all of the things necessary such as sewers, ruins, a river, nearby mountains, nearby woodlands, etc. So switching what we're doing to an existing city like that wouldn't be painful really.

Thanks for the recommendation.

It impressed the heck out of me when I first bought it (it was essentially published as a Kickstarter campaign, years before Kickstarter existed), and I haven't regretted the purchase since then. I haven't yet gotten around to actually run a campaign in it, but always want to one day (though I wouldn't use Dungeon Fantasy - I have my own unique campaign setup in mind which would use GURPS Powers).

I've already created a bunch of racial templates for the Ptolus-specific races and submitted them here - the relevant templates are Elves of Ptolus (also known as Shoal Elves), Harrow Elves ("cursed elves"), Litorians ("lion folk"), and Lizardfolk (also known as "assari").

Ptolus also allows the opportunity to play more unusual and even monstrous races. For one thing, Ptolus is already known across the continent as "the city where all those adventurers and weirdos hang out". For another, there is an organization known as the "Brotherhood of Redemption" in the city who believe that all life is sacred and none is beyond redemption. They also don't exactly value free will, or even believe in it... so they use a magical process to turn "evil monsters" "good". They used to capture them by themselves, but these days they just pay adventurers to bring them the monsters alive...

One more thought: The city does have the printing press (as well as some steam technology, although it is largely in decline and only used among certain obscure organization) - and "sheets", primitive newspapers. So if you (or your players) want to put in the effort, you could publish "sheets" referring to the misadventures of individual groups for the other players to see.

And speaking as a GM, there is little more fun than misrepresenting the shenanigans of player characters in the press. :D